Process for recording sound for talking machines



Dec. 8, 1931. KUHENME|$TER 1,835,164

PROCESS FOR RECORDING SOUND FOR TALKING MACHINES Filed Oct. 4. 1926 @712 vezz'iozv Patented Dec. 8, 1931 UNITED STATES HEINRICH Kl 'GHENMEISTZER, OF BERLIN, GERMANY PROCESS FOR RECORDING SOUND FOR TALKING MACHINES Application filed October 4, 1926, Serial No.-

The present invention relates to the recording of sound for talking machines.

A single recording instrument is excited two or more timesb-y the same sound wave at intervals, preferably of at least 1/30th of a second.

It was not to be foreseen that with such a large phase difierence, satisfactory recording without harmful overlap-ping or losses could be obtained, much less that the tone character in reproduction would be enhanced. One and the same sound wave has never yet been allowed to act on a single recording instrumenttwo or more times, in order to 5 produce a special tone character in recording by a sufficient time interval. Where recording has been done with several sound receivers separated in spaceand acting on a single recording instrument, the space and time intervals have always beensmall, the

time interval being less than a displacement of 1/30th to l/8th second which has'been shown to be the most advantageous. An enhanced tone character has not been observed in recording efiected in this old way.

Figures 1, 2 and 3 are diagrammatic views illustrating difierent applications of the inventiv-e idea.

The time interval is obtained according to the present invention by artificially lengthening the path of the sound emanating from the source 2' for the second excitation-of the sound box'or other recording instrument I) resting on the plate a.

The conduction of the sound to the recording instrument or sound box preferably takes place through two trumpets indicated in Figure 1 of the accompanying drawings by c and d. The time interval in this case 40 is obtained by forming the second trumpet cl with a sufiiciently long tube part 6. As

shown in Figure 2 of the accompanying drawings, however, the sounds can be re- 7 ceived direct by one trumpet g and in addition an inclined Wall k can be provided from 139,339, and in Germany October 13, 1925.

which they are reflected into the second trumpet f. i

The drawings are only diagrammatic and the second sound path is essentially longer. The best effects are obtained only with inv tervals corresponding to a path of 15 or more metres.

Figure 3 of the accompanying drawings shows a further possible way of obtaining the interval. The receiver b. is in the form ,55 of a sound box having an electro-responsive diaphragm and is provided with trumpet 7a. The sound waves from 2' first excite the diaphragm of the sound box I) through the microphone 6 connected by the wires Z, and m then after a sufiicient time interval the sound Waves enter the trumpet is leading to the sound box 6. 1

1. Apparatus for recording 'sound for talking machines including a single sound recording instrument having a diaphragm,

a trumpet operating said instrument, a microphone within range of the source of sound at adistance from said diaphragm, 7

and means for operating said diaphragm from said microphone, said trumpet and microphone being adapted to transmit each sound "wave to said diaphragm at different time intervals to produce reverberations therein. 7

2. Apparatus for recording sound including a recording instrument, a sound transmitting device, electrical means connecting said device with said instrument for carrying sound waves to the latter, and a trumpet for transmitting the same sound waves through the air to said instrument whereby a reverberatory effect is produced in the recorded sound. 7

3. The herein described method of recording sound wherein the sound record produces a reverberatory effect, which consists in transmitting the same sound wave to a single recording instrument 7 through different ,90

channels at least one of which employs air as a transmitting medium.

4. The herein described method of recording sound wherein the sound record produces a reverberatory effect, which consists in transmitting the same sound wave to a single recording instrument through difierent channels to produce a phase shift of 1/30 of a second or more, at least one of said channels employing air as a transmitting medium.

In testimony whereof I have signed my name to this specification.

HEINRICH KUCHENMEISTER. 

